First of all what type of wallet are you using? If you are using web wallet,  follow LADIDAZ's tip to strengthen your password. If your wallet is a desktop wallet, install a good antivirus and always be careful on what you click on the internet, better yet use another desktop for daily use. If it is a hardware wallet, then you are good to go since it is already secure. You can also follow the tip of LADIDAZ to create an offline wallet.